Method of fastening the scraper arms for mechanical roasting furnaces



TING FuRNAcEs.

Jam, E6, w22.

F, AREND ET AL METHOD oF FAsTENrNG THE SCRAPER ARMS FOR MECHANICAL RoAs FILED JAN.

./Wenfofg Fatented l liti, i923..

Ulhtlpl` STATES PATENT FRANZ ABEND, JACOB SCHVVALB, AND WILHELM SONNEIEANN, 0F FRANKFORT-ON- THEJTAIN, GERMANY.

METHOD OF lASTENING 'TI-IE SCRAPER ARBS :MECHANICAL ROASTING- lURNACES.

Application filed. January l1, 1922. Serial No. 528,415.

To all w/Lom it may concern:

Be it known that we, FRANZ Amino, Jason SoHwALB, and l/lirnnniar SoNNn- MANN, residing at F ranlrfort-on-the-li/lain, Schweizerstr. 62, l-lelmholtzstrasse, 29, lifielandstr. 24, Germany, have invented certain new and useful Improvements in Methods of Fastening the Scraper Arms for Mechanical Boasting Furnaces, of which the following is a specification.

The object of the present invention is a method of fastening scraper arms for mechanical roasting furnaces.

rlhe problem on which the invention is based is to provide a firm seating for single scraper arms in their shafts, and in the case of air-cooled arms, to provide that the facings of the air inlet and outlet of the scraper arms abut tightlyagainst vthe facings of the corresponding outlet and inlet of the hollow shaft, whilst avoiding all means such as, for example, screws, loose wedges, braces and vthe like, which may suffer or fail, during` working, through heat, chemical action and the like.

`The invention consists essentially in securing the scraper arm in the pocket of the shaft, by causing two slanting or wedgeshapedprojections, which are cast on the shaft and scraper arm respectively, to press against each other, and by causing the rear vertical edge of the end of the scraper arm to hear against a thrust block provided in the shaft'pocket. the arm being held and locked in its seating during working by the opposing pressure of the material to be roasted.

In order to understand the invention more clearly, reference is made to the accompanying drawings, which show by way of example an embodiment of the fastening device for the arms applied to an air-cooled srraper arm.

Fig. l shows, partly in section, pa rt of the scraper shaft with the arms inserted therein.

Fig. i2 is a cross section at the same part of the shaft.

Fig. 3 shows a front elevation of an arm pocket in the shaft.

Fig. i is a cross section through the scraper arm close up against the shaft, along the line X-X of Fig. l.

The cast scraper shaft H, is provided with two scraper arm pockets B opposite each other. rlhese pockets taper towards the interior of the shaft (see Fig. Each. pocket is provided in front at its upper side with a cast on, slanting or wedge-shaped projection F, and at the rear end at the upper side with projections J, and blocks l adapted to take up the thrust. inasmuch as the example shows an air-cooled scraper arm, air inlet openings Gr branching off from the shaft `bore L, are provided at the bottom of each scraper arm pocket and air exit openings G1 are provided at the top which lead to the hollow spaces M of the shaft.

The scraper arm has the usual shape tapering towards the point.. It is hollow and is divided by means of a cast partition O, into an upper and lower air channel; the lower channel is provided with an air inlet opening and the upper one with an air outlet opening, these openings facing the corresponding openings G, G1 of the shaft pocket.

That end of the scraper arm which is to be inserted into the shaft is of rectangular` cross section and is slightly tapered, correspending to the shaft pocket. The depth to which the end of the arm penetrates into the shaft pocket is determined by the stop l@ provided on the body of the arm. The cxtreme inner end of the arm is provided with a nose C, which, in the working position, lits behind the projection J of the shaft pocket, thus preventing the scraper arm from falling out. A slanting or wedgeshaped projection is cast onto the arm at D. and corresponds to the slanting or wedgeshaped projection F of the shaft pocket so that the inclined surfaces of these wedgeshaped projections D and F when slipped upon each other, occupy the same plane, i. e., that they tighten each other up under pressure. Moreover, in the working position the vertical edge N of the end of thescraper arm hears tightly against the block K which takes up the thrust.

The scraper arm is secured in the shaft pocket in the following manner: The scraper arm, for example A2, is inserted into the arm pocket in the tilted position shown 011 the left-hand side of Fig. l until the stop E abuts against the shaft, and the nose C comes into position behind the projection J. rthereupon the scraper arm is lowered to its normal position (Fig. l right-hand side A1), thus causing the nose C of the end of the scraper arm to viit behind the -wshown inFig. 2, in full lines, so rthat the` projection J ofthe scraper arm pocket.

The arm lis thenin the position shown inw surfaces of the Wedge-shaped projections D of the scraper arin and F of thefarni. pocket bear against each other. The purpose of ,i these ivedgesshaped or slant-ing surfaces is,

firstly, to pressA the tightening surfaces (t. `and G1 connecting the airI passages'rnilytogether, and secondly, in4 conjunction with the thrust block K, to ensure the arin being securelyheld in the iarn'i pocketwW-hen the hollow shaft is revolved. When in work,

the-arm is irnily-iixedi and Vsecured in the` lshaft to the counter pressure of the niaterial to be roasted.` The-nose C and the stop E serve to secure the scraper -ar1n against shifting longitudinally in the Iarm pocket,

I especially in the event of the Iarm Working lmovement of thelshaft.

loose and` being dislodged from its working: position into the position of insertion `(Fig.y

2, dotted), through an accidental reverse l forward movementrthe armiis automatically tightened up again by means' of its-Wedge- I lshaped or slanting projection.

The securing device may be used not only with air-cooled scraper-arins, but also with.,

ordinary scraper arms lunprovided with air coolingchannels In this case, ofcourse, the

communicating openings land theI corre l sponding tightening surfacesl are dispensed with. What We claim is:

l. In aroasting furnace, the combination.V

of a` rotary shaft, a pocket inthe shaft, a wedge extending substantially across the entireividth` of the pocket, a scraper arm seated Within theipocket, and awedge on the scraper arm cooperating with the Wedge on the pocket toihold the arm against rotary displacement when in motion and when at rest.

2. In a roasting furnace, the combination of a rotary shaft, apocket inthe shaft, a Wedge of slight inclination extendingsubstantially across the top face of the' pocket, a scraper arm` seatedwvithin the pocket, and a Wedge projecting upivadly from the top of the arm cooperating'ivith the Wedge on In the subsequent the pocket to hold the arm firmly in position when in motion and fvvhen at rest.

3 In a roasting furnace, the combination of a rotary shaft, a pocket in the shaft, a

, singlescraper arm seated Within the pocket,

Wedges on the pocket and arm which under theopposiiig pressure exerted by the material being roasted cooperate to lock the arin in the. pocket and hold it against rotary displacement relative to the shaft when in motion and when at rest, and means on the farm cooperating with the pocket holding the arm against longitudinal displacement.

et.' In a roasting furnace, the combination of a rotary-shaft, a pocketin the shaft, an air-cooled scraper arm seated Within the pocket, an air passage in the arm having inlet and outlet openings: situated near the `inner end ofthe arm, an air passage in the shaft having openings into the pocket corresponding to .the air openings in the arm, wedges on the pocket and arm 4Which under the opposing pressure exerted by the material being roasted` cooperate to loclr the arm in the pocket andhold it aga-inst rotary dislplacement and hold the corresponding air openings inarm and pocket in operative engagement. A

In a roasting furnace, the lcombination of al rotary shaft, a pocket in the shaft, an

air-cooled scraper Iarm seated Within the pocket, an air passage in the arm having inlet and outlet openingsy situated near the inner end of the arm, one on the upper and one on the lower face thereof, an air passage in the shaft-having openings into the pocket corresponding tothe air openings in the arm, alivedge of slight inclination entendingl substantially across the top of the pocket, and a Wedge projecting upwardly from the top face of the arm cooperating with the Wedge on the pocket to hold the -armwagainst rotary7 displacement, and hold the corresponding air openings in arm and pocket in operative engagement.

In;testimony-whereof We: afHX ourA signatures in presence of two Witnesses.

. i FRANZARENI). JACOB SCI-IWALD.

v WILHELM SONN EMAN N.

vWitnesses Iij H. ANDERSON, Il. R. lSoMMeRHorr. 

